Two teenagers arrested in relation to the killing of a journalist during a riot in Londonderry have been released without charge.
Lyra McKee, 29, was shot dead on Thursday as she watched Irish nationalist youths attack police following a raid.
She was an award-winning journalist who was writing a book on the disappearance of young people during decades of violence in Northern Ireland.
"Two males, aged 18 and 19 ... have been released without charge," the Police Service of Northern Ireland said in a statement.
The men were detained under anti-terrorism legislation and had been taken to a police station in Belfast for questioning.
Detective Superintendent Jason Murphy said: "We have received very positive support from the community but we need to convert this support into tangible evidence that will enable us to bring Lyra's killers to justice.
"I know there will be some people who know what happened but are scared to come forward but if you have information, no matter how small, please contact detectives."
This comes after he said a new breed of terrorist is emerging through the ranks in Northern Ireland.
DSI Murphy said: "What we are seeing is a new breed of terrorist coming through the ranks and that for me is a very worrying situation."
He said there had been a sea change in community attitudes and that was demonstrated in the revulsion expressed by many at Thursday evening's killing.
The published author, from Belfast, was shot in the head by suspects who police believe were dissident republicans linked to the New IRA.
This happened as they clashed with police on the Creggan estate in Londonderry.
Mobile phone footage, released by police on Friday, appeared to show the masked shooter fire a handgun towards police and onlookers including Ms McKee.
